Technical Field
The present disclosure relates to surgical systems, and more particularly, to systems and methods of inducing atelectasis or pulmonary consolidation.
Description of Related Art
Tens of millions of people suffer from lung disease, such as emphysema, chronic obstructive pulmonary disease (“COPD”), asthma, or cancer. Diseases such as emphysema result in poor airflow due to a breakdown of lung tissues. In patients suffering from emphysema the alveoli are no longer elastic and can become enlarged due to walls between the alveoli breaking down. As a result, the alveoli lose their shape and become floppy. This damage from emphysema leads to fewer and larger air sacs instead of many tiny ones. These large alveoli may be called bullae. One result of this breakdown of the alveoli is that the relative amount of gas exchange that can occur in a given unit of time is reduced as the surface area of these fewer enlarged alveoli is less than the many smaller alveoli. Additionally, the weakened floppy alveoli expand during an inhalation. Because of the weakened condition, the air having entered the weakened alveoli cannot be forced out of the lungs during exhalation as a consequence of the decreased elastic recoil of the lungs resulting in the collapse of airways in front of or more proximal to these diseased areas, thus trapping the air in the weakened alveoli. The trapped and thus, deoxygenated, air merely occupies space in the chest and takes up precious volume in the chest cavity that might otherwise be used for gas exchange. As a consequence, the volume available for effective gas exchange of oxygen and carbon dioxide in the chest decreases, thereby resulting in substantive clinical effects such as hypoxemia or on occasion, hypercarbia
A patient suffering from emphysema will typically appear thin, and take more rapid, albeit lower volume, breaths. However, those breaths will occur at higher volumes thus further creating a mechanical disadvantage for the respiratory muscles thereby further exacerbating the clinical problems. As can be imagined, the problem of easy filling and poor emptying of the lung leads to progressive hyperexpansion of the lungs, increased residual volume, reduced capacity, inefficient breathing mechanics, and in general, a continually worsening patient condition as they struggle to breathe. The classic description is that the patient will appear as a “pink puffer,” because the patient will be constantly working in an effort to inspire any oxygen into their overinflated lung tissues.
Chronic bronchitis is the result of excessive mucus build-up in the bronchioles. Often this mucus production is part of an inflammatory response caused by injury to the airways from smoking and other inhaled antagonists. The mucus can be so excessive that it overcomes the ability of the cilia within the lungs to sweep the mucus out and allow it to be expelled. Further, the mucus limits the size of the airways through which air must travel in the lungs, thus limiting the volume of air that can be inhaled. The combined effect causes a sufferer to persistently cough in a futile attempt to clear the mucus. This mucus can be so excessive that as it is drawn further and further distal in the lungs (e.g., to the alveoli which might not themselves be inflamed) the mucus limits the gas exchange as it coats the alveoli walls. The mucus reaching the alveoli further exacerbate the challenges of gas transfer experienced by smokers, where tar and other contaminates may already be covering the lining of the alveoli creating a barrier for gas exchange. Further, the mucus and other contaminants are a breeding ground for bacterial growth, promoting further infection and even greater bronchitis symptoms. The classic description of someone suffering from chronic bronchitis is a “blue bloater.” The color refers to the lack of oxygen successfully transferring form the alveoli to the blood stream and CO2 being expelled from the blood stream through the alveoli to the atmosphere. These patients often appear bloated due to the elevation of carbon dioxide in the blood as well as the decreased oxygen content in the context of water retention as a result of their compromised pulmonary and circulatory functions. As will be appreciated, many if not most patients will suffer from both emphysema issues and chronic bronchitis issues.
Fully functioning alveoli can often adapt and at least partially compensate for the reduction in total lung capacity caused by emphysema COPD. Indeed, this is one reason for the highly invasive Lung Volume Reduction Surgery (LVRS), where the top portions of the lungs are removed in the hope that the remaining tissue will allow the lung to function more efficiently. In part, this improved performance is enabled by the increase in space afforded to the remaining alveoli as well as to improve the mechanics of the respiratory muscles when these portions of the lung are removed. By reducing the lung size, the remaining lung and surrounding muscles (intercostal and diaphragm) are able to work more efficiently. This makes breathing easier and helps patients achieve greater quality of life.
Aside from the highly invasive LVRS, the standard of care for lung diseases, such as asthma and COPD including emphysema and chronic bronchitis has been focused largely on pharmaceutical treatment modalities. For example, ADVAIR®, a bronchodilator is currently marketed by GlaxoSmithKline plc. for the treatment of COPD. Again, surgical treatment is invasive and alternative approaches such as denervation can result in the disablement of whole or parts of functions of the nerve that affects contraction of the damaged alveoli.
While these treatment options are effective to a point, the primary prescription for patients suffering from COPD is simply the administration of oxygen. Oxygen can alleviate some symptoms but does nothing to treat the underlying diseases.
Further, the highly invasive procedures described above may give rise to myriad complications due to insufficient data available to clinicians regarding the effectiveness of the treatment correlated to patient data. Without sufficient data, and outside of the certain, quite limited, subgroups of patients, clinicians are unable to predict the effectiveness or consequences of the procedure which can be, as mentioned, quite invasive and in certain cases worsen outcomes. Accordingly, a need for an improved method of determining and predicting the effectiveness of lung resection is needed.